[bugfix] Raise error FOJS0007 on missing Fn namespace on elements passed to fn:xml-to-json

Closes eXist-db/exist#5543

Author: adamretter

exist-core/src/main/java/org/exist/xquery/functions/fn/FunXmlToJson.java

@@ -276,8 +276,7 @@ private String unescapeEscapedJsonString(final String escapedJsonString) throws
 
     private void checkNamespace(final String namespaceUri) throws XPathException {
         if (!Function.BUILTIN_FUNCTION_NS.equals(namespaceUri)) {
-//            throw new XPathException(this, ErrorCodes.FOJS0006, "Element was in namespace: " + namespaceUri + ", but should have been in namespace: " + Function.BUILTIN_FUNCTION_NS);
-            LOG.warn(ErrorCodes.FOJS0006.getErrorQName() + ": Element was in namespace: " + namespaceUri + ", but should have been in namespace: " + Function.BUILTIN_FUNCTION_NS);
+            throw new XPathException(this, ErrorCodes.FOJS0006, "Element was in namespace: " + namespaceUri + ", but should have been in namespace: " + Function.BUILTIN_FUNCTION_NS);
         }
     }
 }

exist-core/src/test/java/org/exist/xquery/functions/fn/FunXmlToJsonTest.java

@@ -22,7 +22,6 @@
 
 import org.exist.test.ExistXmldbEmbeddedServer;
 import org.junit.ClassRule;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.xmldb.api.base.XMLDBException;
 
@@ -50,7 +49,6 @@ public void arrayInFnNs() throws XMLDBException {
         assertEquals("[\"Curly\",\"Larry\",\"Moe\"]", result);
     }
 
-    @Ignore("Enable in FunXmlToJson#checkNamespace(String) see: https://github.com/eXist-db/exist/issues/5543")
     @Test
     public void arrayOutsideFnNs() {
         final String query =
@@ -84,9 +82,8 @@ public void mapInFnNs() throws XMLDBException {
         assertEquals("{\"Fruit\":\"Apple\",\"Vegetable\":\"Carrot\"}", result);
     }
 
-    @Ignore("Enable in FunXmlToJson#checkNamespace(String) see: https://github.com/eXist-db/exist/issues/5543")
     @Test
-    public void mapOutsideFnNs() throws XMLDBException {
+    public void mapOutsideFnNs() {
         final String query =
             "fn:xml-to-json(\n" +
                 "  <map>\n" +